Vertical load certainly isn't going to be a problem, didn't even put a blip on my spread sheet with the full weight of the walls bearing on only the sills. I also used EWP numbers as they are the weakest values I had handy.

As long as your 'Bensonite' post tennon is 4" long (minus relief for sill shrinkage) so it engages both timbers you will be fine with the 4x6. Just take care not to torque it during assembly. I'd tuck it inward on the post to allow as much relish as possible for the sills' end grain.

Are you doing this square rule?

I might...It depends on the $$ vs. time thing. Right now I'm just floating ideas around.
*K

TG: That was a stock photo of a drawing I did for one of my workshop frames.
When I print a 2d drawing of a joint I like to add a 3d view to show the student what the whole thing will look like.
NH: I understand your point. But this frame has several "general frame rules", and one rule is that the layout of tenons and their mortises are 2" off the reference face and then 2" thick/wide. So with this cross sill (the one with the tenon) connecting to the long sill (the one with the mortise and floor joist drop in pockets) joint, this rule has been met.
Another rule for this frame is that all joints are reduced to the next 1/2" smaller in size (of the actual timber). This is shown by the reduction of the tenon on the inside of the frame.
These two rules are just some of the rules we use when doing square rule joinery, on non planed timbers.
(I'm just posting this as some general info for others not familiar with square rule joinery).

Jim Rogers

You guys rock!
Thanks for the input, I learn so much from your conversations - valuable stuff!
*K

Hi Jim and all:

Great response Jim but I have just one last comment about the corner joint.

Could you tell me why in the majority of cases that the historic frames that I have examined use a half lap fastening on the corners, rather than just relying on a 2 " tendon to hold things together.

I always used the half lap connection because it was what was used in all the original structures that I reproduced , and it seems to me that the half lap would be stronger equalizing the relish left on both timbers

What do you all think

NH

NH:
most of the old frames around me use the m&t at sill corners....

Hi Mark and all--good discussion and input

that is very interesting Mark, but there you go, no one should say only one way to do everything, right!

Many of the barns that I have inspected had bottom mud sills 12" square.

(this is just a comparison)

So if you used a mortise and tenon attachment at the corners, the strength of the corner would have to rely on the strength of a 2 by 11 tenon, or 22square inches of wood.

if you used a half lap the strength of the corner would rely on a 6 by 11 or 66 square inches of wood or 3 times as much holding power.

This is just my observation, I am sure that the corners were done in both methods, I have never noticed or seen the mortise and tenon used at the corners, but then there is alot of things that I haven't seen, it is nice to hear that you have seen this method used and share it here with everyone.

NH

Bingo! That's what I was looking for! (Found out some great stuff along the way, though!) That along with Raphael's spread sheet works for me.
Any disputes....?
Ok. So then, what to do about the floor....? :rolleyes:
I'll get to that later.

couple of things
most of the old frames I've looked at use a m&t that is 1/4 the size of the timber, so in a 12x12 I would expect a 3" tenon, the most common size barn timber around me is 10x10, most often with 2 1/2" tenons.
The other thing is that I disagree that a 4x6 is a timber. It needs to be 5" thick before it is a timber. Just a technical point.

here...let me get out my timber pencil and jot this down...
OK - so, in order for this shed to classify as a timber frame as opposed to a common stick frame, I should use 5x6....aaawwww, now what do I do???